examples: update the cors example to be easier for beginners

And update the pug view engine's vendor jade template engine to yesterday version 1 (tested and worked) to fix https://github.com/kataras/iris/issues/1125


Former-commit-id: 0ea7a8dd97ab13e5ecf984c379234cc671f5d84e

_examples/experimental-handlers/cors/simple/client/main.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"github.com/kataras/iris"
+)
+
+// NOTE: THIS IS OPTIONALLY.
+// It is just an example of communication between cors/simple/main.go and your app
+// based on issues that beginners had with it.
+// You should use your own favourite library for HTTP requests (any programming language ofc).
+//
+// Replace the '8fc93b1c.ngrok.io' with a domain which
+// exposes the cors/simple/main.go server side.
+const url = "http://8fc93b1c.ngrok.io/api/v1/mailer"
+
+var clientSide = []byte(`<script type="text/javascript">
+fetch("` + url + `", {
+	headers: {
+	  "Content-Type": "application/json",
+	  "Access-Control-Allow-Origin": "*"
+	},
+	method: "POST",
+	mode: "cors",
+	body: JSON.stringify({ email: "mymail@mail.com" }),
+});
+</script>`)
+
+func main() {
+	app := iris.New()
+	app.Get("/", func(ctx iris.Context) {
+		ctx.Write(clientSide)
+	})
+
+	// Start and navigate to http://localhost:8080
+	// and go to the previous terminal of your running cors/simple/main.go server
+	// and see the logs.
+	app.Run(iris.Addr(":8080"))
+}

_examples/experimental-handlers/cors/simple/main.go

@@ -1,23 +1,32 @@
 package main
 
-// go get -u github.com/iris-contrib/middleware/...
-
 import (
 	"github.com/kataras/iris"
-
-	"github.com/iris-contrib/middleware/cors"
 )
 
 func main() {
 	app := iris.New()
 
-	crs := cors.New(cors.Options{
-		AllowedOrigins:   []string{"*"}, // allows everything, use that to change the hosts.
-		AllowCredentials: true,
-	})
+	crs := func(ctx iris.Context) {
+		ctx.Header("Access-Control-Allow-Origin", "*")
+		ctx.Header("Access-Control-Allow-Credentials", "true")
+		ctx.Header("Access-Control-Allow-Headers", "Access-Control-Allow-Origin,Content-Type")
+		ctx.Next()
+	} // or	"github.com/iris-contrib/middleware/cors"
 
 	v1 := app.Party("/api/v1", crs).AllowMethods(iris.MethodOptions) // <- important for the preflight.
 	{
+		v1.Post("/mailer", func(ctx iris.Context) {
+			var any iris.Map
+			err := ctx.ReadJSON(&any)
+			if err != nil {
+				ctx.WriteString(err.Error())
+				ctx.StatusCode(iris.StatusBadRequest)
+				return
+			}
+			ctx.Application().Logger().Infof("received %#+v", any)
+		})
+
 		v1.Get("/home", func(ctx iris.Context) {
 			ctx.WriteString("Hello from /home")
 		})
@@ -35,5 +44,5 @@ func main() {
 		})
 	}
 
-	app.Run(iris.Addr("localhost:8080"))
+	app.Run(iris.Addr(":80"))
 }